The present invention relates to a folder device. In particular, the present invention relates to a device designed to fold one terminal portion of an elongated piece of sheet material through 180.degree. in relation to the remainder of the piece.
The invention finds application to marked advantage in the art field of packaging generally, and in the field of packaging of commodities for smokers in particular; indeed reference is made specifically to this very application throughout the disclosure, albeit no limitation in general scope being implied.
In conventional packaging systems, the operation of bending one portion of a piece of sheet material through 180.degree. would be effected by means of a unit comprising two distinct folders arranged in series, one of which would be a fixed folding element generally of helical geometry.
To the end of reducing the relatively cumbersome dimensions of such folding units, U.S. Pat. No. 4,188,024 discloses a device in which an elongated piece of material is bent through 180.degree. by the action of a single folder provided in the form of a flat rod which is capable of movement generated along a predetermined operating trajectory by two distinct transmission linkages, of which the embodiment and control involve notable drawbacks in terms of construction and cost.